Remove MetaNode. (#501)

Author: tobiasraabe

docs/source/changes.md

@@ -137,6 +137,7 @@ releases are available on [PyPI](https://pypi.org/project/pytask) and
 - {pull}`376` enhances the documentation for `pytask dag`.
 - {pull}`378` conditionally skips test on MacOS.
 - {pull}`381` deprecates `@pytask.mark.parametrize`. (Closes {issue}`233`.)
+- {pull}`501` removes {class}`pytask.MetaNode`.
 
 ## 0.3.1 - 2023-12-25
 

docs/source/reference_guides/api.md

@@ -245,8 +245,6 @@ The remaining exceptions convey specific errors.
 Protocols define how tasks and nodes for dependencies and products have to be set up.
 
 ```{eval-rst}
-.. autoprotocol:: pytask.MetaNode
-   :show-inheritance:
 .. autoprotocol:: pytask.PNode
    :show-inheritance:
 .. autoprotocol:: pytask.PPathNode

src/_pytask/database_utils.py

@@ -11,7 +11,7 @@
 from sqlalchemy.orm import sessionmaker
 
 if TYPE_CHECKING:
-    from _pytask.node_protocols import MetaNode
+    from _pytask.node_protocols import PNode
     from _pytask.node_protocols import PTask
     from _pytask.session import Session
 
@@ -66,7 +66,7 @@ def update_states_in_database(session: Session, task_signature: str) -> None:
         _create_or_update_state(task_signature, node.signature, hash_)
 
 
-def has_node_changed(task: PTask, node: MetaNode) -> bool:
+def has_node_changed(task: PTask, node: PTask | PNode) -> bool:
     """Indicate whether a single dependency or product has changed."""
     # If node does not exist, we receive None.
     node_state = node.state()

src/_pytask/node_protocols.py

@@ -14,19 +14,18 @@
     from _pytask.mark import Mark
 
 
-__all__ = ["MetaNode", "PNode", "PPathNode", "PTask", "PTaskWithPath"]
+__all__ = ["PNode", "PPathNode", "PTask", "PTaskWithPath"]
 
 
 @runtime_checkable
-class MetaNode(Protocol):
-    """Protocol for an intersection between nodes and tasks."""
+class PNode(Protocol):
+    """Protocol for nodes."""
 
     name: str
 
     @property
     def signature(self) -> str:
         """Return the signature of the node."""
-        ...
 
     @abstractmethod
     def state(self) -> str | None:
@@ -36,12 +35,6 @@ def state(self) -> str | None:
         does not exist, you can also return ``None``.
 
         """
-        ...
-
-
-@runtime_checkable
-class PNode(MetaNode, Protocol):
-    """Protocol for nodes."""
 
     def load(self, is_product: bool) -> Any:
         """Return the value of the node that will be injected into the task.
@@ -55,11 +48,9 @@ def load(self, is_product: bool) -> Any:
             user calling :meth:`PNode.load`.
 
         """
-        ...
 
     def save(self, value: Any) -> Any:
         """Save the value that was returned from a task."""
-        ...
 
 
 @runtime_checkable
@@ -74,19 +65,32 @@ class PPathNode(PNode, Protocol):
 
 
 @runtime_checkable
-class PTask(MetaNode, Protocol):
+class PTask(Protocol):
     """Protocol for nodes."""
 
+    name: str
     depends_on: dict[str, PyTree[PNode]]
     produces: dict[str, PyTree[PNode]]
+    function: Callable[..., Any]
     markers: list[Mark]
     report_sections: list[tuple[str, str, str]]
     attributes: dict[Any, Any]
-    function: Callable[..., Any]
+
+    @property
+    def signature(self) -> str:
+        """Return the signature of the node."""
+
+    @abstractmethod
+    def state(self) -> str | None:
+        """Return the state of the node.
+
+        The state can be something like a hash or a last modified timestamp. If the node
+        does not exist, you can also return ``None``.
+
+        """
 
     def execute(self, **kwargs: Any) -> Any:
         """Return the value of the node that will be injected into the task."""
-        ...
 
 
 @runtime_checkable

src/_pytask/reports.py

@@ -17,27 +17,27 @@
 
 
 if TYPE_CHECKING:
+    from _pytask.node_protocols import PNode
     from _pytask.node_protocols import PTask
     from rich.console import Console
     from rich.console import RenderResult
     from rich.console import ConsoleOptions
-    from _pytask.node_protocols import MetaNode
 
 
 @define
 class CollectionReport:
     """A collection report for a task."""
 
     outcome: CollectionOutcome
-    node: MetaNode | None = None
+    node: PTask | PNode | None = None
     exc_info: OptionalExceptionInfo | None = None
 
     @classmethod
     def from_exception(
         cls: type[CollectionReport],
         outcome: CollectionOutcome,
         exc_info: OptionalExceptionInfo,
-        node: MetaNode | None = None,
+        node: PTask | PNode | None = None,
     ) -> CollectionReport:
         return cls(outcome=outcome, node=node, exc_info=exc_info)
 

src/pytask/__init__.py

@@ -39,7 +39,6 @@
 from _pytask.mark_utils import set_marks
 from _pytask.models import CollectionMetadata
 from _pytask.models import NodeInfo
-from _pytask.node_protocols import MetaNode
 from _pytask.node_protocols import PNode
 from _pytask.node_protocols import PPathNode
 from _pytask.node_protocols import PTask
@@ -97,7 +96,6 @@
     "Mark",
     "MarkDecorator",
     "MarkGenerator",
-    "MetaNode",
     "NodeInfo",
     "NodeNotCollectedError",
     "NodeNotFoundError",